A technology for generating a large amount of a gas mixture of hydrogen and oxygen; that is, a Brown gas, in a short time by the electrolysis of water to use this gas in a melting furnace, a combustion furnace or the like has already been disclosed in Patent Document 1. Moreover, a Brown gas generator for realizing such a technology is available on the market and, for example, a Brown gas generator manufactured by B.E.S.T. KOREA CO., LTD. is known (www.browngas.com).
Furthermore, a gas generation device suitable for such a Brown gas or an electrolytically generated gas is disclosed in Patent Documents 2 and 3, and structures of an electrolytic cell, a positive electrode, a negative electrode, and an intermediate electrode arranged between the two electrodes are also known.    Patent Document 1: Japanese Patent No. 3130014    Patent Document 2: Japanese Patent Application Laid-Open No. 2004-137528    Patent Document 2: Japanese Patent Application Laid-Open No. 63-303087